The present invention relates to an optical fiber coupler, and more particularly to an apparatus and method for fabricating the same.
Generally speaking, there are three methods for fabricating an optical fiber coupler at present, namely, the etching method, the polishing method and the fusing method. The latter is the most popular method but still suffers from the following disadvantages:
1. The torch adapted to heat the optical fiber strand is held immovable which makes the fusing zone relatively small and thus makes coupling of the optical fiber strand difficult.
2. Upon heating, the optical fiber strand is pulled simultaneously by a single pulling stage at its one end. Consequently, the spliced portion intends to be fused will keep on moving toward the pulling direction which results in an uneven fusing and increases the optical loss of the produced optical fiber coupler.
3. Since the spliced portion is directly heated by an immovable torch, it cannot be entirely evenly heated.
4. The fused optical fiber strand having a relatively fragile fused zone is directly packaged which increases the possibility of breakage of the optical fiber coupler during packaging and thus reduces the yield of the produced optical fiber coupler.